Encoders are used to measure angular or linear motion. A common use of encoders is for computer numeric control (CNC) machines. Encoder housings may be made of metal, e.g., in a bearing encoder, or plastic, e.g., in a modular encoder, and may include printed circuit boards (PCB).
In some situations, it may be desirable or a requirement to eliminate noise on encoder signals, e.g., due to a ground loop. This may be achieved by electrically connecting, i.e., grounding, the PCB to the motor to which the encoder is mounted. In modular encoders, the surface of the housing that contacts the motor is made of non-conductive plastic. In some situations, an O-bracket and a wire may be soldered to the PCB to create an electrical connection between the PCB and the motor. However, this may be both costly and labor intensive.
A metal encoder housing of a bearing encoder may directly electrically couple the PCB to the motor. However, metal encoders may be expensive to produce.
The plastic encoder housing of a modular encoder may be coated to provide a ground path for an enclosed PCB thereof. However, a coated plastic encoder housing may be subject to failure if the coating becomes abraded due to use and/or the coating may be expensive to produce.
A plastic encoder housing may additionally or alternatively be provided with an external wire that may be soldered to provide a ground path for the PCB. An external soldered wire may be difficult and/or expensive to produce and may also be subject to failure due to bending or stressing of the solder bond.